Centric recorder



9 w. H. JENSEN 2,876,541

CENTRIC RECORDER Filed Sept. 24, 1954 INVENTOR we ZZ'EJ'H Jensen BY mm a W ATTORNEYS United States Patent CENTRIC RECORDER Walter H. Jensen, Stockton, Calif. Application September '24, 1954, Serial No. 458,054

Claims. (Cl. 32-19) This invention relates generally to, and it is a major object to provide, a novel centric recorder for use in connection with the manufacture of artificial dentures; a centric recorder being a device by means of which the centric relation of the elements of an artificial denture can be properly established by what is known as a gothic arch tracing.

Another important object of this invention is to provide a novel centric recorder for the purpose of effectively producing the gothic arch tracing and then locating and locking the pre-fitted upper and lower bite blocks in true centric relation.

An additional object of the invention is to provide a novel centric recorder which includesin novel combination-a tracing plate carried by the upper bite block, a scribing pin unit supporting plate carried by the lower bite block, and a locating template adapted for cooperation between said plates. 7

A further object of the invention is to provide novel staples for locking the assembly of parts together in centric relation after the gothic arch tracing has been made and the parts thereafter properly located by the template.

A still further object of the invention is to provide a centric recorder Which facilitates the manufacture of artificial dentures, both as to the operative steps required of the dentist who takes the initial impressions, and the dental technician who produces the artificial dentures therefrom.

It is also an object of the invention to provide a centric recorder which is designed for ease and economy of manufacture; the parts of the centric recorder being relatively simple in structure.

Still another object of the invention is to provide a practical and reliable centric recorder, and one which will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is a perspective view of pre-formed upper and lower bite blocks in open position and with the cooperating plates of the centric recorder afihred thereto.

Fig. 2 is an under side plan view of the upper bite block showing the locating template as secured to the tracing plate carried by said bite block.

Fig. 3 is a front elevation showing the upper and lower bite blocks closed in centric relation, with said bite blocks, and the parts of the recorder, all secured together by the novel staples which the device includes.

Fig. 4 is an enlarged fragmentary transverse sectional elevation taken on line 44 of Fig. 3; the plates, as well as the intermediate locating template, being spaced apart slightly more than in practice, for the purpose of, clear illustration of the wax as used between said parts.

r 2,876,541 Patented Mar. 10, 1959 said bite blocksas usual-being of a hard dental wax.

After the forming and pre-fitting of the bite blocks 1 and 2 for proper engagement in the patients mouth, a,

generally U-shaped, fiat, upper or tracing plate 3' is aflixed to the bite rim of the bite block 1, while a generally U-shaped, fiat, lower or scribing pin unit support-' ing plate 4 is afiixed to the bite rim of the bite block 2;'

both the plates 3 and 4 opening inwardly, and said plates being arranged for substantially matching relation when the bite blocks are closed.

The plates 3 and 4 are preferably aifixed to the wax bite blocks by first heating said plates and then engaging them with such bite blocks.

The plate 3 is formed with an upstanding peripheral rim 5, while the plate 4 is formed with a depending peripheral rim 6; said rims being embedded in the corresponding bite blocks when the plates are secured thereto.

These rims not only serve to locate the plates 3 and 4 against lateral displacement, but additionally the upper rim 5 serves a further purpose, as will hereinafter appear.

The lower, generally U-shaped plate 4 is fitted-on each side-with a pair of scribing pin units 7; said scribing pin units-on each sidebeing spaced front to rear, and disposed so that they are in the approximate zones of the molars and bicuspids.

As each of the scribing pin units 7 is identical in structure to the others, a description of one will sufiice for all.

Each scribing pin unit 7 comprises a socket 8 which is fixed to, and depends from, the lower plate 4 into the bite block 2.

A scribing pin 9 projects from within the socket 8 through a guide bore 10 in the upper end thereof; the pin terminating some distance above said bore. At its lower end the pin 9 is enlarged, as at 11, and a compression spring 12 is engaged in the socket 8 between said lower end 11 and the closed bottom of said socket.

Above the guide bore 10 the pin 9 is formed with an enlarged integral collar 13; said collar initially being disposed, -by the action of the spring 12, a distance above the upper surface of the lower plate 4. See Fig. 1.

The lower plate 4 is formed, on opposite sides, with cut-outs or openings 14, and at the front with a cut-out or opening 15; the openings 14 and 15 serving the purpose as will hereinafter appear.

The numeral 16 indicates a flat, U-shaped locating template of generally the same shape as the plates 3 and 4; said template having bores 17 therethrough in matching relation to the upstanding scribing pins 9.

The thickness of the template 16 is at least as great as the length of the scribing pins 9 above the collars 13. On the under side, at both sides and at the front, the

template 16 is formed with groups of indentations 18 I which are disposed on said template in substantially the in the manner hereinafter described; eachv staple being relatively wide and formed at the upper end with an inturned, downwardly opening, full width hook 20. At the bottom each staple 19 includes an inwardly projecting, full width, saw-tooth tongue 21.

In use of the centric recorder the upper bite block 1 and lower bite block 2 are placed in position in 'the patients mouth after the upper plate 3 and lower plate 4 have been affixed to said bite blocks; the under or exposed surface of the upper plate 3 having smears 22 of tracing ink or the like applied thereto in zones corresponding to the positions of the scribing pin units 7 on the lower plate 4.

Thereafter the patient closes his mouth, which disposes the bite blocks 1 and 2 in closely adjacent relation, with the upper ends of the scribing pins 9 bearing against the under surface of the plate 3. The patient then goes through a series of motions, working his jaws to and fro both forwardly and laterally, whereby the pins 9 scribe gothic arch tracings 23 in the smears of tracing ink 22 on plate 3. As the pins 9 are downwardly yieldable but spring-pressed upwardly, each pin is assured of positive scribing contact on the upper plate 3, compensating for any slight unevenness which may exist between said upper plate and the lower plate 4.

After the gothic arch tracings 23 are scribed on the upper plate 3, as above, the bite blocks are removed from the patients mouth and the locating template 16 is aflixed to the under side of said plate 3 by sticky wax 24 and in position with the bores 17 alined with the center points of the corresponding gothic arch tracings 23; the groups of indentations 18 being disposed outwardly.

Also, small pieces of deformable cushion material, such as plastic wax 25, are disposed in the openings 14 and 15 of the lower plate 4 before the bite blocks 1 and 2 are-returned to the month by the patient.

Upon return of the bite blocks 1 and 2 to the patients month, he again closes said blocks and goes through a series of motions, working his jaws to and fro both forwardly'and laterally, until the pins 9 drop into the corresponding bores 17 of the locating template 16 which is now affixed by wax 24 to the upper plate 3. This locates the upper bite block 1 and lower bite block 2 in true centric relation, as is requisite to the subsequent manufacture, from said bite blocks, of properly fitting dentures.

As the length of the pins 9 above the collars 13 is less than the thickness of the template 16, said pins do not project above the template in the final assembly of the parts.

The pieces of plastic wax 25 disposed in the openings 14 and 15 compress and spread out during the time that the patient is working his jaws to cause register of the pins 9 in the bores 17; such pieces of wax tending to maintain the lower plate 4 stable, i. e. to prevent any sliding, tipping, or cradle motion thereof during the jaw action which locates the pins 9 in bores 17, as aforesaid.

The groups of indentations 18 provide for the reception of aportion of the plastic wax 25 so that there is not undue lateral distribution of such wax when it is compressed and spreads out under the pressure imparted by movement of the locating template 16 toward the lower plate 4.

Upon the pins 9 being engaged in the bores 17, the upper bite block 1 and its plate 3, and the lower bite block 2 and its plate 4, together with the locating template 16 therebetween, are locked up in unitary relation, and before removal of the assembly from the patients mouth, by means of two or more of the staples 19.

Such staples, heated to penetrate the wax of the bite blocks, are disposed in spaced relation about the assembly, with the hooks 20 engaged over the upper peripheral rim of the plate 3, and with the saw-tooth tongues 21 penetrating the lower bite block 2 below the peripheral rim 6 of the plate 4. This secures or locks the bite blocks 1 and 2, along with the parts of the centric recorder, together as a unit, whereby to maintain the proper centric 3 herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the q invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired.

1. A centric recorder for pre-fitted upper and lower bite blocks having bite rims, said recorder comprising cooperative upper and lower plates generally corresponding in configuration to said bite rims, means securing the plates on the corresponding bite rims of the blocks so that the plates will be disposed in adjacent .but spaced facing relation when said blocks are in.

closed position, a plurality of spaced sockets depending from the lower plate so as to depend into the lower bite block, scribing pins extending from within said sockets through the lower plate to a termination thereabove, and spring means in the sockets yieldably urging the pins upwardly; said pins projecting into scribing engagement with the upper plate in said closed position of the bite blocks.

2. A centric recorder, as in claim 1, including an enlarged collar on each pin below its upper end but above the lower plate whereby to limit motion of said pins against the spring means; each socket having a guide bore at its upper end through which the related pin slidably extends.

3. A centric recorder and locator for prefitted upper and lower bite blocks having bite rims; said recorder and locator comprising cooperative upper and lower plates generally corresponding in configuration to said bite rims, means securing the plates on the corresponding bite rims of the blocks so that the plates will bedisposed in adjacent but spaced relation when the blocks are in a closed position, scribing pins mounted in spaced relation on the lower plate on each side thereof andprojecting upwardly into engagement with the upper --.plate in said closed position of the blocks, meansreleasably connecting and locking the bite blocks in closed position, a locating template of substantially the same configuration as the upper plate and having bores therethrough in matching relation to the pins to receive the same when the blocks are in closed position, and a sticky substance disposed between the upper plate and the template and securing the same together.

4. A centric recorder and locator for prefitted upper and lower bite blocks having bite rims; said recorder and locator comprising cooperative upper and lower plates generally corresponding in configuration to said bite rims, means securing the plates on the corresponding bite rims of the blocks so that the plates will be disposed in adjacent but spaced relation when the blocks are in a closed position, scribing pins mounted in spaced relation on the lower plate on each side thereof and projecting upwardly into engagement with the upper plate in said closed position of the blocks, means releasably connecting and locking the bite blocks in closed position, a locating template of substantially the same configuration as the upper plate and having bores therethrough in matching relation to the pins to receive the same when the blocks are in closed position, means releasably securing the upper plate and template together, the lower plate being formed with a plurality of spaced openings therein facing and alining with the template when the bite blocks are in said closed posi tion, and a deformable cushion material disposed in References Cited in the file of this patent said openings and projecting above the lower plate for UNI compressing engagement by the template. TED STATES PATENTS 5. A device, as in claim 4, in which the template, 1,119,051 Snow Dec. 1, 1914 on the face thereof adjacent the lower plate, is formed 5 2,220,734 Shanahan Nov. 5, 1940 with groups of identations substantially registering with 2,562,106 Leathers July 24, 1951 said lower plate openings so as to receive a portion of the deformable cushion material when the latter is subjected to compression. 

